Abstract: Disclosed is an overvarnish unit for applying varnish to a web of printed material as a protective overlay. The overvarnish unit includes a varnish fountain for receiving paste varnish, a form roller, and a plurality of rollers intermediate the fountain and form roller. The form roller engages an impression cylinder roller forming part of a printing assembly. The varnish is transferred from the fountain to the form roller by the intermediate rollers which also mill the varnish as it is being transferred to reduce its viscosity. The form roller is driven at a peripheral speed greater than the linear speed of the web over the impression cylinder roller. This form roller overspeed provides a smearing action in applying the varnish to the web rather than a one to one or line by line printing action thus achieving control over the thickness of the applied varnish and the appearance of the final product.

Abstract: A device which provides an economical means for coating offset plates on one side with a solvent based coating. An offset plate is advanced along a feed table by a suction belt toward a roller assembly consisting of a fountain roller, a metering roller, a coating roller and an impression roller. The fountain roller transfers liquid from a supply of coating liquid to the metering roller which transfers a predetermined amount of liquid to a moving plate by the coating roller. The impression roller forces the plate into engagement with the coating roller. A photoelectric sensor detects the leading edge of the plate as it moves through the roller assembly and moves the impression roller toward the coating roller to begin the coating application. The sensor detects the trailing edge of the moving plate and retracts the impression roller to stop the coating application. The speed of the feed belt, discharge belt and rollers are synchronized to accurately control the thickness of the coating applied to the plate.

Abstract: An automatic integrated processor which sequentially develops, washes and, if desired, applies gum to the exposed surface of an offset photolithographic plate in appropriately separated processing stages. The exposed surface of the plate is subjected to a linear, reciprocating rubbing action by plural sponges, which rubbing action produces results surprisingly similar to those produced by a manual rotary action. A fully assembled processor of this invention requires only that it be connected to a water supply, a source of power, and to a reservoir for used, waste fluids. A single electric motor is adapted (a) to drive plural pairs of coupled drive rolls, (b) to reciprocate the sponges in frictional contact with a generally horizontal offset plate and (c) to agitate angularly disposed containers for developer and gum. The translation of the rotary motion of the electric motor to linear reciprocation in mutually orthogonal planes is effected by direct rod-actuated drives with swivel rod-ends.

Abstract: An automatic self-contained basic unit-processor for an offset photolithographic plate which may be used, at different times, for any processing step requiring contacting of the plate by liquid. For example, an exposed plate is developed by contacting the exposed surface of the plate with the conventional developing fluid, and subjecting the surface to a linear, reciprocating rubbing action by a sponge. This rubbing action produces results surprisingly similar to those produced by a manual rotary action. A fully assembled basic-unit processor of this invention requires only that it be connected to a source of power, and to a reservoir for recirculatable processing fluid. A single electric motor is adapted (a) to drive each roll of two pairs of coupled drive rolls, (b) to reciprocate a sponge in frictional contact with a generally horizontal offset plate, and (c) to supply a controllable flow rate of fluid for processing the plate.

Abstract: An automatic self-contained basic unit-processor for an offset photolithographic plate which may be used, at different times, for any processing step requiring contacting of the plate by liquid. For example, an exposed plate is developed by contacting the exposed surface of the plate with the conventional developing fluid, and subjecting the surface to a linear, reciprocating rubbing action by a sponge. This rubbing action produces results surprisingly similar to those produced by a manual rotary action. A fully assembled basic-unit processor of this invention requires only that it be connected to a source of power, and to a reservoir for recirculatable processing fluid. A single electric motor is adapted (a) to drive each roll of two pairs of coupled drive rolls, (b) to reciprocate a sponge in frictional contact with a generally horizontal offset plate, and (c) to supply a controllable flow rate of fluid for processing the plate.